1. The September 11 attacks on the World Trade Center were carried out by 19 terrorists affiliated with al-Qaeda, who hijacked four commercial airplanes and deliberately crashed them into the Twin Towers of the World Trade Center and the Pentagon.

2. The attacks on September 11, 2001, resulted in the death of 2,977 people, making it the deadliest terrorist attack in world history.

3. The cleanup and recovery efforts at the World Trade Center site continued for almost nine months after the attacks, with hundreds of workers laboring to remove debris and identify human remains.

4. The site of the World Trade Center was eventually transformed into a memorial, museum, and plaza, with the centerpiece being the 9/11 Memorial reflecting pools, which feature the names of all the victims of the attacks.

5. The September 11 terrorist attacks had far-reaching impacts on American society and politics, leading to the wars in Afghanistan and Iraq, heightened airport security measures, and a yearning for national unity and resilience in the face of tragedy.